Delhi Gas Chamber: Dense fog diverts flights, air quality in 'very poor' category

Air Quality Index (AQI) in Delhi: Aya Nagar, Anand Vihar and Delhi University's North Campus recorded the worst air quality in the city, where the Air Quality Index (AQI) went above 400 on Wednesday, which falls in the 'severe' category, according to data from the Central Pollution Control Board (CPCB).

Delhi's air quality fell into the 'very poor' category on Wednesday morning, and a thick layer of fog engulfed the city. The Indira Gandhi International Airport diverted some flights headed to Delhi due to poor visibility.

According to the India Meteorological Department (IMD), dense fog started forming around 5:30 am, which led to poor visibility across the city. The Air Quality Index (AQI) rose from 316 on Tuesday evening to 370 on Wednesday morning. Many areas of Delhi recorded AQI above 300.

Aya Nagar, Anand Vihar and Delhi University's North Campus recorded the worst air quality, where the AQI crossed 400, which falls in the severe category, according to data from the Central Pollution Control Board (CPCB).

Other areas whose AQI was above 300 included Anand Vihar (396), Jahangirpuri (389), ITO (378) and IGI Airport (368).

Delhi's 24-hour average AQI was recorded at 361 at 8 am on Tuesday.

Visibility in Delhi is likely to clear by noon, helped by low-altitude surface winds and urban heat island effect. However, visibility in parts of Punjab and Haryana is likely to remain poor till afternoon. Visibility has already improved to 400 metres in some areas of Delhi, such as Safdarjung.

Visual reports from several parts showed that visibility dropped to almost zero, and vehicles were seen using fog lights on the roads.

Indira Gandhi International Airport issued an advisory, stating that flights not CAT III compliant may be affected due to the fog.

"Landings and take-offs are continuing at Delhi airport, but flights that are not CAT III compliant may be affected. Passengers are requested to contact the respective airline for updated flight information. We regret any inconvenience caused."

Visuals from the Delhi-Meerut Expressway also showed reports of almost zero visibility in the region.

One of the main reasons for this dense fog is the presence of dense smoke in the atmosphere. This smoke, combined with dust particles, acts as a nucleation site for water vapour, which helps in the formation of dense fog and reduces visibility rapidly, especially at ground level.